Adjusting soil pH - am I doing this right?

I am feeding my plants with the Fox Farm line of nutrients and am growing in soil. I alternate each time I water with using straight water and then feeding nutes as per the Fox Farm instructions.

Every time I water/feed my plants I check the pH of the runoff and try to keep it as close to 6.5 as possible by constantly adjusting the pH of my water/nute mix.

So for example, if the pH of my runoff is 6.0, then the next time I water I may use 7.5 pH water and then check the pH runoff and it will hopefully be 6.5.

Is this the correct way to go about it? What is the highest I can allow the pH of my water/nute mix to be? I have one plant I have to use 9.2 pH water to get the pH of the runoff to be around 6.5. Is this hurting my plants?

Attached are some photos - plants are 6 1/2 weeks into 12/12. I have 2 Barney's Farm LSD feminized, 1 DNA Genetics LA Woman feminized, and 2 G13 Labs Thai Super Skunk.

As far as I understand, you must ph test a soil sample from the root zone to know soil ph. The runoff ph doesn't really correspond to the soil's ph since the runoff doesn't benefit from buffering components in the soil.

I only concern myself with the ph that goes in, not what comes out.

$0.02

i Have a quik question.. Will the nutes change the ph if the water is perfect ph. 6.2... if i had something akailan like rhinoskin. how much would it bring the ph up? its is soilless mix that is buffer with lime to so it wont go over 7ph. Lets say just its at 7.. would it go to 6.2 if i water with 6.2 nute mix? that is a little acidy>? or would it go down more? cant someone elaborate on ph ? thanks

mr.smileyface said:

i Have a quik question.. Will the nutes change the ph if the water is perfect ph. 6.2... if i had something akailan like rhinoskin. how much would it bring the ph up? its is soilless mix that is buffer with lime to so it wont go over 7ph. Lets say just its at 7.. would it go to 6.2 if i water with 6.2 nute mix? that is a little acidy>? or would it go down more? cant someone elaborate on ph ? thanks

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I'd get some ph test drops or some other method of ph testing.

The nutes I use definitely change the ph of my water.

Hawk said:

I'd get some ph test drops or some other method of ph testing.

The nutes I use definitely change the ph of my water.

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I have a ph pen.. it says 6.2. .. would that make the soiless ph 6.2?

Like I said, I just pay attention to the ph of what's going in. I try to use a high quality organic soil and let the soil do whatever it does after I've supplied it with ph adjusted water or nute solution.

I use soil and know little about soiless mixes (although I think I've read they prefer lower ph values than soil requires).

Yea well it basicly hyrdo. they like 5.5-6.2. instead of 6-7 for soil. Your not understanding my question, sorry. Lets just say your soil is a nutrual 7 and you want to lower it. So you water with 6.2 ph leveld water. would it bring it to 6.2 or 6.5 or somewhere around there?

mr.smileyface said:

...Lets just say your soil is a nutrual 7 and you want to lower it. So you water with 6.2 ph leveld water. would it bring it to 6.2 or 6.5 or somewhere around there?

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I don't think there's a one-size-fits-all answer to that. Different soil compositions can/will react at different rates. One soil might readily have its alkalinity/acidity changed while another will be harder to change. Just depends on what's in the soil.

In any case, I thought soils' ph should be changed by adding a composition material--peat, lime, wood ash, whatever--not by adding water or nutrient solutions of a "counteracting" ph.

$0.02